That wound is not unusual and very typical, I have seen many like that, for some of the bullets that are going too fast for design at impact.
The Accutip is running 1900 FPS (3") and says it is bonded for controlled expansion from 5-200 yds. Obviously not in your case.
Many of the shotgun slugs are designed to expand down to less than 1000 FPS, much like a pistol bullet. Because they can expand at those low velocities it makes them frangible at close range with the higher barrel velocities.
In the smokeless MZ's those that shoot the SST, and 240 gr. XTP shows wounds exactly like you experienced, that is why few shoot them anymore. The power belts, out of BP MZ's are also notorious for that of performance and wounds.
In my opinion, if you shoot a shotgun slug that uses a Barnes all copper bullet, you have the best bullet performance available for the complete range of velocities